1. Вычислите: 1) 2/3 + 5/8; 4) 6/35 + 3/10; 7) 11/48 - 5/36

1. Вычислите: 1) $\frac{2}{3} + \frac{5}{8} = \frac{16}{24} + \frac{15}{24} = \frac{31}{24} = 1\frac{7}{24}$ 4) $\frac{6}{35} + \frac{3}{10} = \frac{12}{70} + \frac{21}{70} = \frac{33}{70}$ 2. Найдите сумму: 1) $12\frac{3}{8} + 8\frac{1}{6} = 12\frac{9}{24} + 8\frac{4}{24} = 20\frac{13}{24}$ 3) $9\frac{8}{21} + 4\frac{11}{14} = 9\frac{16}{42} + 4\frac{33}{42} = 13\frac{49}{42} = 14\frac{7}{42} = 14\frac{1}{6}$ 3. Найдите разность: 1) $7\frac{5}{6} - 3\frac{2}{3} = 7\frac{5}{6} - 3\frac{4}{6} = 4\frac{1}{6}$ 3) $11\frac{11}{12} - 5\frac{7}{9} = 11\frac{33}{36} - 5\frac{28}{36} = 6\frac{5}{36}$ 7) $\frac{11}{48} - \frac{5}{36} = \frac{33}{144} - \frac{20}{144} = \frac{13}{144}$ 1. Выполните умножение: 1) $\frac{5}{6} \cdot \frac{3}{20} = \frac{1 \cdot 1}{2 \cdot 4} = \frac{1}{8}$ 2) $\frac{3}{7} \cdot \frac{6}{11} = \frac{18}{77}$ 3) $\frac{10}{11} \cdot \frac{11}{26} = \frac{10}{26} = \frac{5}{13}$ 4) $\frac{24}{65} \cdot \frac{39}{40} = \frac{3 \cdot 3}{5 \cdot 5} = \frac{9}{25}$ 2. Найдите произведение: 1) $4 \cdot \frac{2}{41} = \frac{8}{41}$ 2) $6 \cdot \frac{7}{18} = \frac{1 \cdot 7}{3} = \frac{7}{3} = 2\frac{1}{3}$ 3) $\frac{5}{14} \cdot 28 = 5 \cdot 2 = 10$ 4. Решите уравнение: 1) $10\frac{5}{8} - x = 7\frac{3}{5}$ $x = 10\frac{5}{8} - 7\frac{3}{5} = 10\frac{25}{40} - 7\frac{24}{40} = 3\frac{1}{40}$ Ответ: $3\frac{1}{40}$